I am thinking of getting a new computer and wondered about the Athlon64.

How much difference does a 64 bit processor really make for desktop computing? Will there be a performance gain just through using a kernel compiled for the processor, or do all apps need to be recompiled too for the main benefits?

As I understand it, the big difference is that the 64 bit processor gets code/data in 64 bit words or can. The problem is that 32 bit apps have been compiled as 32 bit words. The result can be a slowing down of performance for 32 bit apps on a 64 bit machine. I've read that even when compiled for a 64 bit machine, they can still slow down.

It seems that the big difference is more the amount of RAM that can be addressed, so making them ideal for big database servers which need fast response so keep much of the data in RAM.

I'm thinking of upgrading myself, but I'm more concerned to get 1GB memory rather than a heftier processor.

If you have a reasonably fast 32-bit processor, plenty of RAM and fast SATA hard drives, then you probably won't notice much difference in day-to-day computing - after all processor speed is not the main bottle-neck slowing your system.
Mostly, I have found compiling software to be somewhat quicker, and encoding oggs is so fast if you blink you miss it. Otherwise I haven't noticed anything outstanding.

I work for a company with a large number of Opterons running RH9, RHEL 3 32-Bit, RHEL 3 64-Bit and RHEL 4 64-Bit. Running your 64-Bit OS and 32-Bit Apps won't give you a speed decrease due to the nature of the AMD x86_64 and it natively being able to run 32-Bit instructions. In fact you might get a speed increase due to the way it handles RAM - but I'm talking >2Gb RAM compared to 32-Bit memory addressing.
What your Athlon64 will give you will be a future for your desktop. It will run all what you need it to run now and the bonus of running the 64-Bit compiled apps when you need to. The 64-Bit compiled programs will give you a speed boost due to the fact that 64-Bits can be shoved through your clock cycles at a time as opposed to 32-Bits. That's more data transfer per click.

But for now I'd say tread wearily. Yes the ram is the area most improved, my desktop has Dual channel modules and they are so bloody fast! BUT! Please note this is not well typed, grammar sucks and i make a few assumptions about the reader but i am just so pissed off (RANT STARTS HERE BE WARNED)the software is a major letdown, I mean the OS overall. I definately get the impression I am running 32bit software 'Hacked' to fit the Athlon 64. Hmmm it's a shame but just today I have had the thought Intel and the Itanium was the correct route!
Qualification? well I have to say yes the ath 64 has backwards compatability, but, *that word again* I am looking to the future. 'I' don't want legacy support, I 'want' 64bit apps for my 64bit chips, whereas what i get now are half hearted efforts. It seems to me the marketing and ignorance/conservatism of customers pulled intel into line. I never thought I'd say this but *again!* Intel of all companies were (between AMD and themselves) the mavericks in 64bit computing not AMD. Now please note this is not from my point of view flaming, just ironic, because I hate Intel with a passion, yet they at least were willing to shrug of the 'old'; AMD have pushed a presently overrated chip which when one installs 64 bit *cough* linux on it, it still ends up running on a mish mash of 32 bit compatability libs. What is the bloody point? If the AMD platform is so great why the *expletive* do you still have developers and vendors churning out half baked 64 bit distros? Because AMD made it possible that's why. Bastards, I feel so let down the promised future just hasn't arrived. Now some may say well these are teething problems. What?! After several years! Heck Intel were slated for coming to market a little early, i refer you to early itaniums *mutter* but they have gotten better. AMD meanwhile after screwing the market in their favour by taking the whole pie *backwards compatability* are now looking to dual core? Same chips just two cores, WTF? But what of the teething problems? In AMD speak...Expletive you ya mug! And so the marketing department marches on.

Oh and yes I do have both Itanium and AMD 64, but Ath 64's are overhyped Athlon XP's atm largely because as I state above the developers and vendors are taking advantage of the backwards bit and being lazy gits. Why write a native 64bit distro when you can hack 32bit to fit? It was on the assumption that i'd be able to use a 64bit distro that I bought a suite of such machines. At first they seemed great until I delved under the bonnet and saw so much non 64bit software in there. really my only overall gain has been Ram and lots of it. That's it the sum value of my opinion on "why you should buy an Athlon 64?" The larger ram, nothing else.
I bought one itanium machine early on and though i was impressed I wasn't pleased, but with the AMD64 i was delighted *I accepted the hype, I mean it is AMD we a talking about, i trusted them* now I'm just pissed.
Maybe as others have stated your machine, if you buy AMD 64 now will have a 'future' but to be honest why not just wait till then? Beef up what you have now and wait.

And further to the above I took 32bit versions of popular distros and 64 bit versions installing both on same Ath 64's, the 32 bit versions were actually faster to install and speedier in that they responded promptly, whereas the 64bit versions were'nt quite sure what to do when asked to fire up an app. Although 64bit apps, and not all apps in a 64bit distro are 64bit, were faster in performance generally, but I do think the ram is the hub of it all. Drives are irrelevant for me as I always use striped raid so they are fast regardless.

hope the above makes sense I'm calmer now, but still gonna whack the first AMD ceo i see!

Intel were not mavericks, they did not have the first 64bit CPU at all. The spec was around in 1991, Alphas were out 92, SPARC was around 93, SGI were around 92/93, the IBM PowerPC etc Intel released Itanium in 2001, 10 years after the first, they were seariously late and over priced and under performed.

The Opteron / Athlon64 is a total success, it was what the mass market wanted, its not an overhyped XP. It's an evolutionary core, with memory controller, north bridge, built into the chip, dual core designed from the outset, cheap (relatively), extremely fast clock for clock compared to others, it still outperforms others in 32bit mode. The Opterons use 55watts, the design is very efficient.

An Athlon64-3200 is faster than an XP3200, runs cooler and can take advantage of the increased memory bandwidth if used with 64-bit apps. Look at any database benchmark and performance is vastly improved in 64-bit mode. A 32bit system is mostly limited to 4GB of RAM, which is not that much, so again 64-bit is needed in so many areas.

It depends on what your doing as to how much benefit your going to get.

Why are you narked with the idea of dual cores, I am really looking forward to these, the AthlonX2's sound great, better performance yet same power usage. Dual cores are one area that should help everyone with using their PC's, again when the software they are using supports it.

AMD have produced a fantastic core in the shape of the Athlon64, and they've managed to market it perfecftly, it works in a huge number of situations. The Opteron make great SMP servers, the Athlon64 is a great home user / desktop PC, the FX is a gamers dream, the Turion offers great performance for very low wattage. I can't see any problems with their range, something for everyone from essentially the same product. Its no different from VW using the Golf platform in other series and other makes.

AMD have done a great job, especially considering the size of the company in comparison to Intel.
64-bit was pitched to the mass market as a marketing ploy, the USP, killer app etc etc But I don't feel conned, I knew it didn't mean that much to me as a home user (database development at work a different story), but the core excels in so many areas that it doesn't matter that KDE doesn't load in 1 second.
In most benchmarks my Athlon64-3200 is nearly twice as fast as my XP1600, yet only 600MHZ seperates the two chips, the Athlon64 is a design classic in the making and theres a couple of years mileage in it for sure.

"Intel were not mavericks, they did not have the first 64bit CPU at all."
You misunderstood my point, between the two, not the rest. Both are the two most prevalent home CPU producers such is why i focus on them, yes i grant IBM are way ahead. Sorry you must forgive my closed world view, I only buy from these two or at least have done since leaving Uni and it's bloody Mac's behind. Oh and the reason I think them "mavericks" is because they took us a large leap away from legacy tech, though as i said the market pulled em into line. My personal view of itanium/AMD 64 is similar to my view on the VHS/betamax, it was economics which gave the vhs prominence not it's tech. Likewise, this one should be clear, Windows/OSS, hmmmmm it's not the tech which got windows onn the desktop by default, it's the marketing and now so many millions believe they wanted windows, indeed the marketing and FUD is crucial, for instance my AMD 64 laptop was obviously prebuilt, so I asked the saleswoman, "can I get a discount for not having windows?" Errrr we can't sell you the laptop without windows was the answer. Apparently she also couldn't understand why i didn't want a 32bit os for my 64bit machine, yet it's because it was 64bit that i was buying it! *ah never mind I'm beginning to rant again* I'm just so angry with the fact AMD chruned out 64bit chips claiming the operating systems were in place or would be by launch yet this is not the case afterall luike I note elsewhere even suse which was touted as 64bit ready and used to demonstrate machines is still littered with 32bit, this is why I think Intel were mavericks, they made this use of i386 nigh on impossible by starting afresh. Okay this was a little ahead of the market but it makes sense to me in that it ensures or makes a good stab at it anyway, of 'making' 64bit, 64bit only. Whereas AMD allowed 32bit to live on through backwards compatability.

"The Opteron / Athlon64 is a total success, it was what the mass market wanted, its not an overhyped XP"

Really? No Kidding, I noted the OS as perhaps and arguably my main quibble.
I am sick of promises, promises, promises, that my install platters are for a 64bit os. Only as i said to find them littered with 32bit apps and libs. I mean why the hell need a 64bit os rely on i386 software? Should I really be expected to tolerate this given I bought the discs because they were 64bit? You wouldn't buy a Rolls Royce and be best pleased if you found it had the engine of a mini, would you?

"An Athlon64-3200 is faster than an XP3200"

Well that's what i thought, note here I believe it is, or should be *basic maths for goodness sake* but consider this, Mandy, pig slow for 64bit and can't handle much of the software, Centos in 32bit version takes 19 minutes to do a complete install, 64bit version of same release takes 112 minutes, I kid you not same machine same hardware etc. You telling me Kubuntu is 64bit ready? or Fedora, Suse et al? I have found they can't support the newer features introduced by the AMD 64 and accompanying hardware Oh and not to mention they run 'slower' in 64bit than 32 this applies from install to desktop/server use. So sorry on that count as far as I'm concerned, and i have a AMD 64 laptop, AMD 64 Desktop and dual opteron, the performance is not a leap, rather a tentative step. Accordingly from experience and bitter dissapointment I find the Ath 64 to be a hyped XP. Hyped in that it promises but does not deliver. Which as I pointed out is a shame because I dearly want AMD to do well, no really, I have thought them marvellous since I got my first k6 running at a woeful 150Mhz and thought *wow*.

"Why are you narked with the idea of dual cores, I am really looking forward to these, the AthlonX2's sound great, better performance yet same power usage. Dual cores are one area that should help everyone with using their PC's, again when the software they are using supports it."

That's the rub of it Nordle, "when the software they are using supports it" at present I find no adequate os to consistently support the AMD 64 platform as is. There is fault with all those noted above. Though one thing I must add I do find certain kernels to be awful and exacberate matters. Why? Well probably because as another topic of discussion led to the conclusion that vendors cherry pick the kernel modules! *boggle* Fedora being my most hated for it, with Mandy coming close, though it has a different take on it, by including everything bar the kitchen sink and it errrrr not working! *damn*
So moving to dual core won't be a blessing as the OS *even Windows* just ain't cutting the mustard, they can't support the technology already ushered in by AMD and the attendant potential, so what chance of working dual core?

" AMD have done a great job, especially considering the size of the company in comparison to Intel."

Partially why i want them to do well, as I'm not happy about corporations, though largely because liek i said above my first AMD was a k6 150 and it was notably more capable the intel's offerings.

"64-bit was pitched to the mass market as a marketing ploy, the USP, killer app etc etc"

So it wasn't? " what the mass market wanted" you don't need to market on hype what people are asking for it's an open market, so yes AMD are guilty of a hard sell, and the buyers are suckers, me included I guess.

As it happens I agree the Ath 64 is an advance and does *theoretically excel* but the software doesn't. I too have ran benchmarks in 32/64 bit and each and every time it's only on ram that the 64bit wins. So yeah it may be cooler but it ain't much further ahead. The Itanium I have, is an early model and like I said it wasn't good, but then intel managed to pull their finger out and get some adequate support in place so it picked up. So far AMD's flagship just ain't cruising! Why? because the software simply isn't in place and because as I implied it allows for compatability, which both developers and vendors equate with laziness, re i386 etc *grrrr* Yes I do feel conned i wanted 64bit not 32bit and then some ie hyped XP. So again i would say wait for the market to mature, oh and at risk of repeating myself if the market had demanded it why the heck do we have to wait for it to mature before it works? I do believe AMD sold on promises, afterall consider demonstrations of Ath 64's were running on linus anmely suse yet I personally find suse to be unable to fully support the tech, how tweaked were those boxes i wonder. Come on pull the other one it has bells

Oh one thing as I finish this, I am actually looking into an IBM machine on the power platform, at least i'll get reliable multi core, *multi core in a dual cpu box drooooool* and of course reliable cpu and hardware support.

OK, so you're feeling let down because most of the apps you run are still 32-bit.
Well, there is a solution - put Gentoo on your shiny new AMD64 box. That way all your apps are compiled in 64-bit mode and you should be able to get the most out of your hardware...

I will indeed look into Gentoo, and kudos to you for reading my long grumble!
I'll post back no doubt *fingers crossed i'll be raving about gentoo!* Oh but it will be a while as I'm switching ISP's and it may take a few weeks, apparently it takes upto 30 days to switch off my current ISP and a further ten to switch on my new one *boggle* No doubt I'll be complaining about that too LOL.
Anyways take care all.

regards Zara...

Oh I'm changing ISP because apparently near constant downloading is frowned upon as being "beyond fair and reasonable use"! But I'm paying for unlimited it's not my fault I just can't stop finding operating systems and software to download. And yes I am concentious in that I help seed legal torrents, again this is frowned upon. I really don't see the problem as I'm the only one in my street with broadband so who the heck am I affecting? *ack i'm ranting again!*

nelz wrote:By a lucky coincidence, LXF68 will have Gentoo for AMD64 (as well as X86 and PPC) on the DVD.

Good grief Nelz you never miss the mark! You really are the creme de la creme, I wish I had the job of finding and trying new software! Anyways it's on order as usual and Lord help the newsagent if they can't get it, *i'll be complaining about that too!*

Oh it's something I'm gonna be reliant upon because of ISP change I noted above.

>>
I am thinking of getting a new computer and wondered about the Athlon64.

How much difference does a 64 bit processor really make for desktop computing? Will there be a performance gain just through using a kernel compiled for the processor, or do all apps need to be recompiled too for the main benefits?
>>

Basically all apps, but as mentioned above, 32 bit compatability is assured, so there is no problem running existing apps. In a 32 bit system it will probably be seen as an i686.

You could apply athlon specific switches if you like -mcpu=athlon -march=athlom -mmx -msse etc.

But info gcc will give be able to give a better description of options than i could, and you'll find the kind of flag range thats's available via /proc/cpuinfo.

>>
Does anyone have any stats on the subject?
>>

www.hexus.net have heaps of archived reviews on lots of related topics,

for one, but it would probably be better to just search around the site, as they have a lot of stuff archived.

The general drift i get though is, that the Athlon64 3000+ will out do the XP 3200+ by app 80 %, and also do the P4 at around 20 to 25%, all at half the clock too !.

And as mentioned above, you have a future. Go for Socket 939 not the 754.

I just put in a Athlon64 3000+ and am extremely happy with it. But then thats to be expected, as i was coming from a 200mmx i586 ... like, any bigger hamster would be great in that case

Ignore zarathustra's rant on the availability of 64 apps and it being all AMD's fault because of it maintaining 32 bit compatability , (or maybe it was the shop girls fault) ... thats just a load of mad rubbish

Go for it, over here in Aus, at least, it is the best buy in the processor market at the moment You don't get any real cache increases untill 4000+ (around that mark), and they don't look cheap.